FiiO JM21 Digital Audio Player with 4+64GB Memory

The FiiO JM21 puts flagship-level audio chips into an entry-level Android music player, and this is the version with 4GB of RAM, 64GB of storage and a bigger battery for up to 16 hours of listening. Two Cirrus Logic CS43198 DACs in a fully balanced design deliver up to 700mW per channel from the 4.4mm output, a 6nm Snapdragon 680 runs a smooth Android 13 for your streaming apps, and FiiO’s DAPS system keeps every app bit-perfect. It is just 13mm thin and 156g, and won both a Gold Award and a Planning Award at VGP 2025 Summer in Japan.

A 6nm Snapdragon 680

Inside is a Qualcomm Snapdragon 680 with eight Kryo 265 cores running at up to 2.4GHz, made on a 6nm process, for a big step up in performance with noticeably lower power use and a silky-smooth experience.

Dual CS43198 DACs in a fully balanced design

Two flagship Cirrus Logic CS43198 DACs work with two high-performance SGM8262 op-amps in a fully balanced audio design. Building on lessons from many earlier players, FiiO further optimised the segmented power supply and the front and rear gain stages for wider dynamic range and richer musicality: up to 129dB signal-to-noise from the balanced output, with distortion as low as 0.0006%.

The digital and analogue sections have independent power supplies. A three-stage segmented supply gives the DAC, voltage amplification and current amplification stages their own power, and each op-amp in the four-channel amplifier has four independent precision LDO regulators. The main control, DAC and amplifier sections each sit in their own shielded zone, reducing crosstalk and outside interference for purer sound.

DAPS: no resampling, from any app

Android normally resamples audio. FiiO’s DAPS (Digital Audio Purification System) uses a fifth-generation FPGA with two custom femtosecond crystal oscillators, 10ppm low-drift parts with ceramic gold-plated bases and ultra-low phase noise, each screened by FiiO, to give one precise, low-jitter clock source. Whether you play local music in FiiO Music, stream from Apple Music or another app, or send audio to an external USB DAC, the original sample rate is left untouched.

Three gain levels, three volume curves

Low, medium and high gain each have their own volume curve, so the JM21 suits everything from sensitive earphones to full-size headphones. The 4.4mm balanced output gives 700mW per channel into 32Ω and the 3.5mm output 245mW.

Smooth, customised Android 13

FiiO’s deeply customised Android 13 is intuitive and smooth, and lets you install the major streaming apps. Because Android 13 uses a lot of memory, FiiO recommends focusing on music apps and not running many apps at once, for the best sound and performance. Five modes cover different uses: Android, Pure Music, Bluetooth receiver, USB DAC and AirPlay.

Thin, light and up to 16 hours

The JM21 is just 13mm thin and 156g, easy to hold in one hand, with an aluminium alloy frame and a 4.7-inch HD screen. This 4GB + 64GB version has a 3,100mAh battery for about 16 hours from the 3.5mm output or 12.5 hours balanced (the standard 3GB + 32GB model gives about 12.5 and 9.5 hours). It charges in about 2.5 hours from a 5V 2A charger; it doesn’t support fast charging.

Two-way Bluetooth with LDAC

Two-way Bluetooth 5.0 lets the JM21 send to wireless headphones in LDAC, LHDC, aptX HD, aptX, AAC or SBC, or receive from your phone in LDAC, AAC or SBC, so it can be a hi-fi Bluetooth receiver too. With FiiO Link you can control the JM21’s FiiO Music app from your phone: over Wi-Fi or Bluetooth from Android, and over Wi-Fi from an iPhone.

USB DAC, USB audio, coaxial and line out

Connected to a Mac or Windows computer, the JM21 becomes an asynchronous USB DAC at up to 384kHz/32-bit (FiiO notes slightly higher latency, so it isn’t ideal for video). In the other direction, USB audio output sends up to 768kHz/32-bit and DSD512 to an external DAC through an OTG cable, and the 3.5mm socket doubles as a coaxial output (384kHz/24-bit, DSD128). Both headphone sockets switch to line out for active speakers or an amplifier, and Wi-Fi supports DLNA and AirPlay.

Lights that tell you what’s playing

The indicator light shows the format at a glance. In local playback it glows blue for lossy files, cyan for CD quality, yellow for hi-res and green for DSD; over Bluetooth it shows green for LDAC, yellow for LHDC, purple for aptX and aptX HD, cyan for AAC and blue for SBC. You can set its brightness or turn it off.

Good to know

• This is the 4GB RAM, 64GB, 16-hour version of the JM21.
• Cases: the FiiO NEST POD and the leatherette case for the JM21.
• For more power and FiiO’s desktop mode, see the FiiO M21.
• In the box: JM21, screen protector (fitted), transparent case, USB-A to USB-C cable, quick start guide and warranty card.